Dry cleaning composition



Patented Aug. 17, 1943 DRY CLEANING coMrosrrIou Lawrence H. Flett,Hamburg, N. Y., assig'nor "to Allied Chemical & Dye Corporation, acorpora-\ tion of New York No Drawing. Application November 25, 1938,

Serial No. 242,150

9- Claims.

This invention relatesto improvements in the dry-cleaning of fibrous,textile and related materials. It relates particularly to improvedcompositions for use in dry-cleaning and to processes of dry-cleaning inwhich said improved compositions are employed.

It is well known that certain types of textile fabrics and materialssuch as leather cannot be cleaned by means of. ordinary soap and watersince they are prone to shrink, harden, wrinkle and/or fade when theyare wetted with water. For the cleaning of such materials a dry-cleaningprocess must be used. In such dry-cleaning processes volatile organicsolvents such as naphtha, trichlorethylene, Stoddards solvent, etc. areused; such" solvents are effective in removing from the fabrics ormaterials practically all grease stains as well as dust and dirt whichcommonly adhere to the greasy spots. ther known that if a small amountof water is sufficiently well dispersed in the dry-cleaning fluid, watersoluble stains, such as those caused by sugary liquids, candy, softdrinks, etc., are removed simultaneously without adversely affecting thematerial so treated.

There are available on the market a number of soaps or other alkalinepreparations for use in the dry-cleaning process. These soaps are usedin spite of several very objectionable features. To be effective suchpreparations must be used in large quantities. Soaps and free fattyacids which accompany them are left in the goods where they becomerancid and so cause an objectionable odor. The alkaline reaction affectsthe colors of dyed fabrics. The soaps serve mostly to hold water in thedry-cleaning solvent and do not effect a greatly increased degree ofcleaning.

According to the present invention a dry-cleaning bath is used whichcontains as essential components a dry-cleaning solvent or mixture ofdry-cleaning solvents and at least one salt of a primary alkyl sulfuricacid derivative having at least 4 carbon atoms in an alkyl group. In thepreferred form of the invention, the dry-cleaning bath also contains asmall amount of water dispersed in the dry-cleaning solvent.

The said primary alkyl sulfuric acid derivatives are salts of compoundsof the general formula: RCH2S, where R represents an alkyl radical whichcontains at least 3 carbon atoms and which alkyl radical may contain anintermediate oxygen atom or an ester or acid-amide radical, or itrepresents an alkylated phenyl radical wherein the alkyl group containsat least 12 It is furacid, ;cetyl sulfonic acid, beta-sulfo ethyloleate;

p-lauryl benzyl sulfonic acid, beta-sulfo ethyl ester of ricinoleicacid, beta-sulfo ethyl ester of meth'oxy oleic acid, 9- orIO-chloroctadecyl-sulfuric acid; lauroxy-ethyl sulfonicacid;f9,l0-dichloroctadecyl sulfuric acid, and lauric acid amide ofamino ethyl sulfuric acid.

Sulfuric acid compounds or derivatives of the above described generalclass are found to give excellent results in improving dry-cleaningcompositions, but it has been found that certain of these compounds giveeven better results than the class as a whole. Such preferred compoundsare primary aliphatic monosulfates which contain an alkyl residue of atleast 8 carbon atoms, and preferably at least 12 carbon atoms.

This inventionv contemplates the use of salts of compounds of the abovegeneral formula in which the acidic hydrogen is replaced by an inorganicor organic salt-forming radical. Among the more easily obtained saltsare the ammonium, alkali metal and alkaline earth metal salts. Salts inwhich the acidic groups are neutralized by organicbases. (such as.mono-,dior tri-ethanolamine, pyridine, ethylene-diamine,. amylamine,triethylene-tetra-mine, etc.) may also be v used, however. If thesalt-forming basic radical-.is polybasic, it may be neutralized whollywiththe sulfuric acid compound of the abovegen'eral formula or in partwith such a compound and in part. with other acidic materials, -whichadvantageously mayhave detergent properties. ,Examples of .such otheracid materials arei di-isopropyl naphthalene sulfonic acid, n-propylsulfuric acid, hydrochloric acid, naphthalene sulfonic acid, sulfuricacid, etc.

The presence as dry-cleaning assistants of the hereinbeiore definedorganic sulfuric acid derivatives in a dry-cleaning fluid has beenfoundto be particularly effective in enabling the dry-' cleaning fluidin which water is normally practically immiscible to hold in finelydispersed form a limited amount of water.

It has been found that by using the sulfuric acid derivativesherelnbefore defined a substantially greater amount of water in relationto the amount of dry-cleaning assistant present can be held in a welldispersed form in the dry-cleaning solution than was heretoforepossible. With the dry-cleaning agents herein-defined, the mathe absenceof water with excellent results.

However, better results are usually obtained by adding a small amount ofwater as such to the dry-cleaning bath. Due to the presence of thesulfuric acid compounds the water becomes incorporated and dispersed insuch an extremely finely divided state in the dry-cleaning compositionthat water-sensitive materials can be drycleaned in suchwater-containing dry-cleaning compositions, without fear of waterspotting. The exact amount of water needed in any given case variessomewhat according to the type of soil which is to be removed and thisgenerally varies with the particular material to be treated. Forexample, about 0.25%- of water hasbeen found to give good results inmany cases. In general there must not be so much water present that itis in poorly dispersed form and so causes water-spotting of the materialbeing dry cleaned. As is well known, the amount of moisture which thematerial will tolerate without suffering water-damage (wrinkling,shrinking, etc.) depends upon the particular material and its state ofdryness as well as on the degree of dispersion of the moisture in thedry-cleaning solvents. The amount of water which a drycleaning solventcan hold in a very finely-dispersed or non-wetting state with respect tothe material to be cleaned depends altogether upon the dry-cleaningassistant which is added to the solution, and it has been found that themembers of the class of dry-cleaning assistants hereinbefore defined arevery substantially better for the purpose than those heretofore employedin the art. Practical comparative tests show that the. dry-cleaningcompositions of this invention are substantially better that thedrycleaning compositions used according to the prior art.

An important feature of the compositions of this invention is that theyhave no tendency to become rancid; hence they do not leave or causeobjectionable odors of rancid matter in materials cleaned with them. Thepresence of such odors from matter which is left in the drycleanedmaterial and becomes rancid subsequently is a difficulty which iscommonly experienced with dry-cleaning compositions of the prior art.The dry-cleaning compositions of this invention are free from thisdifficulty. The primary sulfuric acid derivatives hereinbefore definedare more stable than the corresponding secondary or tertiary sulfuricacid derivatives and are, therefore, less prone to release insolubleorganic matter which is apt to be retained in the fiber of thedry-cleaned material and to ive rise to rancid odors.

This improved stability of the sulfuric acid derivatives hereinbeforedefined may be attributed to the presence therein of the primarygrouping CH2SO3 or =CH2OSO3, whereas the secondary or tertiary groups=CHSO3, =CHOSO3, ECSO3 r ECOSO: are less stable. The bonds shown inthese formulas represent linkage to other carbon atoms.

Much of the difliculty caused by rancidity which is found in many of thecompositions of the prior art is also probably due to the use of oleicacid and its salts which are not necessary for the dry-cleaningcompositions of the present invention.

It has been found further that substantial economies in dry cleaning areshown by the use of the hereinbefore defined sulfuric acid compounds inthe dry-cleaning compositions of this assistants per 1000 2,326,772terial to be cleaned may be solvent washed ininvention. This is due tothe fact that much less of the dry-cleaning assistants hereinbeforedefined is necessary to produce an excellent cleaning effect than haspreviously been used of the currently-known dry cleaning assistants.Thus, it has been found, when the primary alkyl sulfates defined aboveare used, that less than one-third of the usual amount of dry-cleaningassistant need be added to the dry-cleaning solvent to prepare adequatedry-cleaning compositions. An outstanding characteristic of the new drycleaning compositions of this application is their ability to attainexcellent cleaning action with very low concentrations of compound,particularly when water is added to the bath in small amounts, Theweight ratio of the sulfuric acid derivative salt to organicsubstantially water-immiscible dry-cleaning solvent or solvent mixtureneed not be greater than 1.0:100 and is preferably less than 3:100. Infact, dry-cleaning compositions co taining between about 1 and about 3parts of the dry-cleaning parts of solvent by weight have been found togive highly satisfactory cleansing.

Although the dry-cleaning compositions of the present invention haveincreased cleaning action yet they have no harmful and undesirableeffects on color and finish of the materials cleaned in them. Further,the sulfuric acid compounds which are incorporated in these compositionsas dry-cleaning assistants are for the most part not lime sensitive, andtherefore they do not form insoluble calcium salts nor cause undesirabledewhich are used in the dry-cleaning compositions' of the presentinvention may be used with excellent results in practically any drycleaning solvet. The presence of the hereinbefore defined sulfuric acidderivatives in the dry-cleaning compositions of the present inventionalso has the very desirable effect of greatly decreasing the internalelectrical resistance of inflammable solvents,-or solvent mixtures;thereby substantially decreasing the danger of fire from sparkdischarges or static electricity.

In many moderndry-cleaning plants it is the practice to removeundissolved dirt from the drycleaning solution by filtration. Thepresence of the sulfuric acid compounds of this application aid indecreasing the clogging effects of the dirt on the filter media andretards the development of back pressures in the filters. In this waythe period during which the dry-cleaning solution can be recirculatedbefore plugging the filter is substantially increased with resultingeconomy in operation. I

The invention i illustrated by the following examples in which the partsare by weight.

Example 1.A cleaning bath was obtained by mixing 3.0 parts of technicalsodium cetyl sulfate with 1115 parts of V, M. P. naphtha, which had aspecific gravity of 0.746, and a boiling range of 215 F. to 320 F, andof which per cent of the distillate distilled between 215 F. and 279 F.A piece of flannel soiled with a mixture of tallow and carbon blackwasagitated mechanically in this dry cleaning composition for about half anhour. The flannel was withdrawn and allowed to dry. Good cleaning actionwas obtained.

In the following Table I, in which Examples 2 to 23 are summarized, thesame procedure was followed; 1. e., the dry cleaning compositions werefirst prepared by mixing the ingredients and then used to clean soiledflannel.

TABLE I SUMMARY OF Exaurms Cleaning compositions E Sulfuric acid deriv.salts Dry cleaning solvents Vax. er No. used Amt. Kind Amt. Kind amt.

Part: Part: i! i! wt. wt. 2 3.0 Sodium cetylsul- 1,115 V. M. P. naphtha.2.5

{agate (techni- 3 1.5 Sodium isobutyl 1,115 -.--d

sulfate. 4 1.5 Sodiumlaurylsul- 1,l15 do fonate. 5 1.5 ...-.do 1,115-.-do.- 2.5 6 1.5 Sodiumsaltofthe 1,115 -do oleic acid ester offl-hydroxyethyl sulfonic acid. 7 1.5 ..-.-do. -do 2.5 8 1.5 doTrichlorethylene" 9 1.5 do o 2.5 10 1.5 .----do Tetrachlorethylene. 111.5 ....-do..... -do 2.5 12 1.5 Gardinol (com- V. M. P. naphtha.

P ili' aury an a esaltfree). 13 1.5 io 1,115 do 2.5 14 1.5 Sodiumn-amyl- 1,115 do sulfate. 15 1.5 -do 1,115 -.d') 2.6 16 3.0 Sofdiumcotylsul- 2,190 Trichlorethylcno oimtc. 17 3.0 .do 2,190 -d0 2.5 18 1.5Sodiumlaurylsul- 2,100 do fouute. 19 1.5 .do 2,190 d0 2.5 20 3.0 Sodiumcctyl sul- 2,390 Tetrachlorethylfouate. one. 21 3.0 -do 2,390 do 2.5 221.5 Sodiumlaurylsul- 2,390 do fonate. Z3 1.5 do 2,390 --do 2.5

In each of the above examples good cleansing r action was obtained. Itwas noted that the drycleaning compositions which contained water inaddition to a dry-cleaning assistant .which was a sulfuric acidderivative represented by the foregoing general formula gave decidedlybetter cleansing action than the same compositions without water.

An improved finish and/or feel of the drycleaned materials can often beobtained by incorporating a small amount of paraflln hydrocarbon orsimilar agent such as paraflin wax or paraflin oil into the cleaningcomposition. Thus the presence of about 0.1 to about 1.0 per cent ofparaflin oil has been found effective for this purpose.

As has been noted above, the hereinbefore defined sulfuric acidderivatives are effective as dry-cleaning assistants in dry-cleaningcompositions made as illustrated in the foregoing examples from naphtha,trichlorethylene and tetrachlorethylene which were used asrepresentative dry cleaning solvents. Similarly, other volatile organicliquids of the dry cleaning type, such as carbon tetrachloride,Stoddards solvent, benzene, gasoline, and even less common substanceswhich are useful as dry-cleaning solvents, may be used.

The defined sulfuric acid compounds which are added as dry-cleaningassistants to form the drycleaning compositions of this invention may beprepared in any convenient manner. The customary sulfonation procedureor any other method of preparation is satisfactory.

The compounds of this invention have been found to give excellentresults in the dry-cleaning of all kinds of materials and fabrics suchas wool, silk, cotton, leather and rayon. The compositions are effectivein the removal of all types of soil, dirt or stains. They may be used inpractically any machinery or device used in commercial dry cleaning andin any type of purifying or recovery process which is applied to thedrycleaning fluid.

The addition of various other products such as other organic sulfuricacid derivatives, soaps, fatty acids, etc. does not substantially affectthe excellent properties of the dry-cleaning compositions of the presentinvention.

In the specification and claims the term sulfuric group includes boththe sulfate group, -OSO3H, and the sulfonic group, -SO:H. The termprimary alkyl sulfuric acid derivative" means an organic compound whichcontains a sulfuric group attached to a primary carbon atom of an alkylgroup, and includes compounds which contain an aromatic nucleus as apart thereof in addition to said alkyl group.

I claim: I

1. A dry cleaning composition comprising an emulsion of water in avolatile organic dry cleaning solvent, the water being in the internalphase, and a salt of an aliphatic organic compound containing an alkylgroup of at least 4 carbon atoms and a sulfuric group attached to aprimary alkyl carbon atom, as a dry cleaning assistant and as anemulsifying agent for the water, said salt being selected from the groupconsisting of ammonium, alkali metal, alkaline earth metal, and organicammonium salts.

2. A dry cleaning composition comprising an emulsion of water in a.volatile organic dry cleaning solvent, the water being in the internalphase, and a salt of an aliphatic organic compound containing an alkylgroup of at least 12 carbon atoms and a "sulfuric group attached to aprimary alkyl carbon atom, as a dry cleaning assistant and as anemulsifying agent for the water, said salt being selected from the groupconsisting of ammonium, alkali metal, alkaline earth metal,

and organic ammonium salts.

3. A dry cleaning composition comprising an emulsion of water in avolatile organic dry cleaning solvent, the water being in the internalphase. and a salt of a primary alkyl sulfate having at least 8 carbonatoms in the alkyl group, as a dry cleaning assistant and as anemulsifyin agent for the water, said salt being selected from the groupconsisting of ammonium, alkali metal, alkaline earth metal, and organicammonium salts.

4. A dry cleaning composition comprising an emulsion of water in avolatile organic dry cleaning solvent, the water being in the internalphase, and a salt of a sulfonated aliphatic organic compound containingan alkyl group of at least 4 carbon atoms and a sulfonic group attachedto a primary alkyl carbon atom, as a dry cleaning assistant and as anemulsifying agent for the water, said salt being selected from the groupconsisting of ammonium, alkali metal, alkaline earth metal, and organicammonium salts.

5. A dry cleaning composition compr sing an emulsion of water in avolatile organic dry cleaning solvent, th'water being in the internalphase, and a salt of a primary aliphatic monosulfate containing an alkylgroup of at least 12 carbon atoms, as a dry cleaning assistant and as anemulsifying agent for the water, said salt being selected from the groupconsisting of ammonium, alkali metal, alkaline earth metal, and organicammonium salts. I

6. A dry cleaning composition comprising an emulsion of water in avolatile organic dry cleaning solvent, the water being in the internalphase, and a salt of an alkyl sulfate having at least 8 carbon atoms inthe alkyl group and a sulfonic group attached to a prima y carbon atom.as a dry cleaning assistant and as an emulsifying alkaline earth metal,and organic ammonium 'salts.

7. A dry cleaning composition comprising an.

emulsion of water in' a volatile organic dry cleaning solvent, the waterbeing in the internal phase, and sodium iauryl sulfate as a dry cleaninassistant and as an emulsifying agent for the water.

8. A dry cleaning composition comprising an emulsion of water in avolatile organic dry cleaning solvent, the water being in the internalphase, and sodium cetyl sulfate as a dry cleaning assistant and as anemulsifying agent for the water.

9. A dry cleaning composition comprising an emulsion of water in avolatile organic dry cleaning solvent, the water being in the internalphase,

and sodium'lauryl sulfonate as a dry cleaning assistant and as anemulsifying agent for the agent for the water, said salt being selectedfrom 20 water,

the group consisting of ammonium, alkali metal,

LAWRENCE H. FLET'I'.

CERTIFICATE or cpnmscrxou. Patent No. 2,526,772. v August 17, 1915,

mwmcr n. FLET'I'.

It is hereby certi-fied that error appea ra in the printed specificationof the above numbered patent requiring correction as followe: Page 2,first column, 1ine58, for "that" read --then--;' and second column, line147-148,

for 'eo1vet' read --so1vent--;'pegeh, first mnfline 16, cllim, for

"sulfate" read---sulfonate--; and that the said Letters Patent should-beread with this correction therein that the same may conform to therecord of the one in the Potent Office. 4

si ed and sealed this 5th a of October, A. n. 1915.

I Henry Van Aradale, (Seal) Acting Commissioner of Patent.

